Packaging lines using aseptic technology are already known, wherein the various operations take place in a controlled contamination environment, so that the bottled products can be stored for a prolonged period of time and have chemical/physical and organoleptic stability even at room temperature.
Aside from differences in design, a “conventional” aseptic bottling line envisages:                forming the receptacle starting with a parison made of a thermoplastic material;        
chemical sterilisation of the formed receptacle;                rinsing, filling and capping of the filled receptacle, to be carried out in a sterile environment.        
The main drawback of conventional lines is related to the need to have to sterilise the receptacle once it has been formed and to maintain the sterilised state thereof throughout all subsequent operations, for example the filling and capping operations.
A modern concept of an aseptic bottling line instead envisages:                sterilisation of the parison using chemical agents or radiation sterilisation;        “aseptic” forming of the receptacle starting with the sterilised parison;        filling and capping of the filled receptacle, to be carried out in a sterile environment.        
In this regard, the Applicant has developed a forming apparatus for forming under aseptic conditions, in which the rotary forming carousel is protected by an isolation device suitable for defining a controlled contamination environment, and the movement means for moving the carousel and moulds is located outside of isolation device (see European Patent EP2246176).
The preliminary sterilisation stage involves all devices that come into contact with the parison subjected to forming by stretch-blowing, including for example the picking members, the stretching rod and the blown air circuit. The Applicant has thus developed ad hoc solutions for the stretching rod (see European Patent no. EP2340157) and for the blown air circuit (see European Patent EP2643142).
In this way the Applicant has developed a completely aseptic blowing machine and a bottling line in which the process zone of each operating unit is protected by a dedicated microbiological isolator, from which the movement and manipulating means of parisons/receptacles is excluded (see European Patent EP2279850). The main drawback of this solution clearly lies in its considerable structural complexity.
It should also be added that not all the manual procedures required during operation (e.g. removal of obstacles) can be performed with the use of handling gloves: in some cases it is necessary to open the access door of the isolator, with a consequent loss of sterility. Upon completion of the procedure, a sterile environment must be restored, resulting in an evident loss of time due to downtime of the line.
The above-mentioned solutions, as well as the structural complexity, are able to ensure maintaining the sterility inside the bottling line which receives the parisons in inlet.
In an aseptic line the sterilisation performances of the receptacles and the closures are expressed by the number of D-value reductions which the sterilisation treatment is able to carry out on a reference microorganism. For example, for aseptic lines which package low-acidity products six D-value reductions are generally requested, while in lines treating high-acidity products four D-value reductions are sufficient.
The sterilisation specifications are very stringent as they take into account events of accidental contamination of an extraordinary nature. On the other hand, in the production process going from the raw material (PET granules) to the formed and capped receptacle there are some passages in which the contamination level is not under control.
In fact, the production of the formed parisons is done in dedicated facilities (known in the sector as converters) starting from the PET granules, which are melted so as to shift the plastic into the viscous state, which is then injected into the moulds of appropriate machines (presses).
In outlet from the press, the parisons are collected in octabins, i.e. cardboard packs having prismatic shape with an octagonal base, which are transported into the bottling facility, where they are stored in a special store. In harmony with the production rate, the octabins are opened and the parisons are tipped loosely into a hopper, in order then to pass to an ordering unit which orientates them with the mouth upwards and supplies them to a machine forming the receptacles (known in the sector as a “blower”).
It is therefore clear that in all steps upstream of the aseptic bottling line the parisons are potentially exposed to high risks of contamination, due both to the manual interventions by the operator (e.g. manual packing of the parisons in the octabins or tipping the parisons into the hopper) or to the damage to the octabins during transport and storage.
It is exactly this absence of control of the contamination in these steps that does not allow for any loosening of the sterilisation performances mentioned above.
However, guaranteeing four or six D-value reductions has a substantial effect on the complexity and the overall volume of the aseptic line, among other things increasing production costs.
For these reasons, in recent years some producers have developed solutions which involve the production of parisons upstream of the packaging line, in the same facility.
The integration of the moulding press of the parisons in the bottling line has however set constraints due to the fact that the press is a machine functioning alternatingly, working on molten plastic material that is very delicate to manage. Further, the press has format-change operations that are rather laborious and long.
For example, document EP2578504 illustrates an aseptic filling system in which all the operating units, including the parison moulding press, are located in a clean chamber. Each operating unit is further contained in a dedicated cabin at higher pressure than that of the clean chamber in such a way as to guarantee a degree of purity that is greater inside the cabin. The operator is afforded access to each cabin in the line.
Similar solutions are also described in documents US2011/0219728 (see in particular the embodiment illustrated in FIG. 2 of that document), EP0794903 and EP2324987.
In this way, reference is explicitly made to the need to sterilise the internal surfaces of the clean chamber and the external surfaces of the cabins/boxes containing the single operating units.
The main drawback of these solutions integrating the moulding press of the parison inside the aseptic line is connected to the increase of the volumes and surfaces to be sterilised before start-up and to the increase in the volumes to be maintained sterile during production.
This means a complication of all the activities involved with sterilising and managing the line. Further the cleaning and sterilising time cycles are lengthened.
A further drawback is due to the increase in complexity of the press in order for it to be compatible with the production rate of the downstream units. For example, document EP2578504 relates to a temporary storage buffer of the parisons between the press and the blower.
In this context the technical task underpinning the present invention is to provide a production apparatus of sterile receptacles, a bottling plant comprising the apparatus and a production method of a sterile receptacle, which obviate the drawbacks of the prior art as cited in the foregoing.